// Copyright (c) 1996-99 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies.  This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason.  IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
// CALIFORNIA HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE, SUPPORT,
// UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

// File: EnumerationSingle.java
// Classes: EnumerationSingle
// Original Author: jrobbins@ics.uci.edu
// $Id: EnumerationSingle.java 1153 2008-11-30 16:14:45Z bobtarling $

package org.tigris.gef.util;

import java.util.*;

/**
 * A enumeration that has exactly one element. Functially equivelant to:
 * 
 * <code>
 *  Vector v = new Vector();
 *  v.addElement(obj);
 *  return v.elements();
 *  </code>
 * 
 * This is useful when you must pass or return an enumeration, but you do not
 * have many elements.
 */

public class EnumerationSingle implements Enumeration, java.io.Serializable {
    Object _element = null;

    public EnumerationSingle(Object ele) {
        _element = ele;
    }

    public boolean hasMoreElements() {
        return _element != null;
    }

    public Object nextElement() {
        if (_element != null) {
            Object o = _element;
            _element = null;
            return o;
        } else
            throw new NoSuchElementException();
    }
} /* end class EnumerationSingle */
